The Urban Dictionary T-Shirt

Literally the worst person on the planet. Will do whatever he can to get in a girl's pants without any care for others' emotions. If you meet an Omer you can immediately identify him as "the guy with the slicked back hair who wears all skate or basketball apparel and likes to say he's good at everything".

John: "Say Mike, look at that guy over there talking to Cheyenne".
Mike: "Oh that's just Omer, watch as he makes bad jokes and slicks his hair every three seconds".
John: "Wow, that guy is a huge tool".